This Fertility Test May Not Be as Accurate as Previously Believed, New Study Shows

If you’re in your mid- to late-30s and trying to conceive, you’ve probably heard from friends or doctors that you might have a harder time — and you might be wondering whether it’s a good idea to get your fertility tested. But a new study suggests that not only is one particular test possibly not all it's cracked up to be, but you may not have so much to worry about as an "older" mom-to-be.

What the study looked at

If you decide to get a fertility test today, one of the main hormones the clinic will be looking at is antimüllerian hormone (AMH). Low AMH levels are considered to be a biomarker, or sign, that you have low ovarian reserve — i.e., fewer eggs left to make babies.

To get a better feel for how accurate AMH levels actually are at predicting whether or not women can get pregnant, from 2008 to 2016 researchers recruited 750 women in North Carolina between the ages of 30 and 44. The women had not experienced infertility and had been trying to conceive for three months or less. Between days 2 to 4 of their cycles, they gave a blood and a urine sample, which the authors then used to measure several fertility-related hormones: AMH, follicle-stimulating hormone (FSH) and inhibin B. The women left with free home pregnancy tests and were told to take them whenever they had missed their period or on day 28 and every three days after.

The authors checked in with the women six and again 12 months later to find out if they’d since had a positive home pregnancy test. They then compared those answers to their AMH levels, taking into consideration outside factors that can affect a woman’s fertility (such as weight, age, whether or not they were currently smokers and how recently they had gotten off of birth control).

What it found

Women who had what were considered "low" AMH levels were actually just as likely to get pregnant within 12 months as those with "normal" levels — 65 percent vs. 62 percent, respectively, got pregnant within six months, while 84 percent versus 75 percent got pregnant within 12 months.

The same was true for FSH: a woman’s levels did not change her likelihood of getting pregnant. And inhibin B levels were not related to a woman’s chance of getting pregnant in any one cycle.

What this means for you

If you want to become a mom and haven’t experienced infertility but are still anxious about how your age might affect your chances of conceiving, this study might come as a relief. In fact, other recent research has found that by age 38, 80 percent of women are able to conceive — which means most couples have an excellent chance of becoming parents for the first (or second or third) time after the age of 35. So instead of rushing to spend $150 or more to get your fertility tested, most doctors will tell you it’s usually a better bet to just go ahead and do the baby dance for a while and see what happens. Chances are very good that you’ll get pregnant within a year. If not (or if you’re over the age of 40 and don’t get pregnant within six months), then it’s time to check in with your doctor and find out if you need further testing to see if anything is up.

With that said, there is a limit to natural fertility. The likelihood of getting pregnant drops to 50 percent by age 41 and approaches zero by age 50. It’s also important to remember that increasing age also ups your risk of a baby with chromosomal abnormalities (like Down syndrome) as well as pregnancy complications (like preeclampsia, gestational diabetes and preterm birth).

Bottom line: if you’re in your 30s and hoping to have a baby, there are plenty of steps you can take to not only make it likelier you’ll conceive but also that you’ll have a healthy pregnancy — eating a well-balanced diet full of fresh fruits and veggies, fiber, lean protein and healthy fats; exercising regularly; getting enough sleep; seeing your doc for all your prenatal appointments; taking the tests your practitioner recommends; and avoiding smoking and alcohol. So live a healthy lifestyle and then try to relax and let nature take its course. Odds are excellent that you’ll be adding to your family very soon.